This topic describes how to create an alert callback to integrate CloudMonitor alerts to your existing O&M or message system.

Background information

CloudMonitor provides the alert callback feature for alert notification in addition to the methods such as emails, and DingTalk Chatbot. Alert callback allows O&M engineers and developers to handle alert events flexibly.

CloudMonitor pushes alerts to a specified Internet URL through HTTP POST requests. You can take actions based on received notification.


  • You have a callback URL that is accessible through the Internet.
  • URL callback is enabled as an alert notification method in your existing O&M or message system.



  • According to the retry policy of alert callback, the number of retries is 3 and the timeout period is 5 seconds.
  • Currently, only HTTP is supported.
  1. Log on to the CloudMonitor console.
  2. Modify an existing alert rule by creating a callback or create an alert rule.
  3. In the notification method section, enter the URL address for alert callback and click OK. When an alert rule is triggered, CloudMonitor sends an alert to your specified URL.

Callback parameters

The following table lists the content of a POST request that is pushed when an alert rule calls back a URL.
Parameter Data type Description
userId String The user ID.
alertName String The alert name.
timestamp String The time stamp when the alert is generated.
alertState String The alert state. One of the following states is returned: OK, ALARM, and INSUFFICIENT_DATA.
dimensions String The object that has triggered the alert. For example: [{"userId":"12345","instanceId":"i-12345"}]
expression String The alert conditions. For example, [{"expression":"$value>12","level":4,"times":2}] indicates that an alert is triggered when the threshold value is greater than 12 for two consecutive times. If the value of level is 4, an alert is sent to you through an email. If the value of level is 3, an alert is sent to you through a text message and an email. The times field indicates the number of consecutive times of reaching the alert threshold that you selected when configuring the alert rule.
curValue String The current value of the metric when an alert is triggered or cleared.
metricName String The metric name.
metricProject String The service name. For more information about the metric and service names, see Preset metrics reference.

An example of a POST request is as follows:

   "expression":"[{\"expression\":\"$Average>90\",\"level\":4,\"times\":2}]" ,